Pipe laying tractor



July 12, 1955 R. A. PETERSON 2,712,873

PIPE LAYING TRACTOR Filed Nov. '22, 1949 5 SheetsSheet 1 EN TOR.

. f? B 197' .4. PETERSON B ATTORNEY July 12, 1955 R A. PETERSON PIPE LAYING TRACTOR INVENTOR. ROBERT A. PETERSON ATTORNEY July 12, 1955 R. A. PETERSON 2,712,873

' PIPE LAYING TRACTOR Filed Nov. 22, 1949 5 Sheets-Sheet 5.

INVENTOR.

ROBE/PT A. PETERSON ATTORNEY R. A. PETERSON 5 Sheets-Sheet 4 July 12, 1955 Y PIPE LAYING TRACTOR Filed Nov. 22, 1949 IN V EN TOR. ROBERT A. PETERSON II N ATTURNEY July 12, 1955 R, PETERSON 2,712,873

PIPE LAYING TRACTOR Filed Nov. 22, 1949 5 Sheets-Sheet 5 INVENTOR.

ROBERT A. PETERSON ATTORNEY United rates PIPE LAvrNo TRACTOR Robert A. Peterson, San Leandro, Califi, assignor to Caterpillar Tractor (30., Peoria, 111., a corporation or California Application November 22, 1%9, Serial No. 128,539

3 Ilairrm (Ci. 2128) This invention relates to an improved tractor of the type having aside boom for lifting, carrying, and lowering objects at one side of the tractor.

ractors of this general type are widely used for transporting and laying in place sections of large-diameter pipe, such as the so-called "big inch pipes that carry oil and natural gas from the wells to the cities. Often a caravan of such tractors is used to carry a single long section of such pipe and deposit it as a unit in a trench.

The only practical location for the boom is at one side of the tractor. This has meant that the full carrying capacity of the tractor could not be utilized, because when the weight of the pipe exceeds a certain proportion of the weight of the tractor, the tractor will be overbalanced and will tip over on its side. The weight which will overbalance a tractor is substantially less than the weight which the tractor would be capable of carrying if the weight were not all to one side. Once the overbalancing Weight has been reached the tractoris usefulness ceases. Thus the potential carrying capacity of the tractor is never fully utilized.

Many attempts at solvin this problem have been made. One was by securing large counterweights to the side of the tractor opposite the boom to balance the weight on the boom side. This did some good, but was not a satisfactory solution because of the loss due to the weight of the counterweight which subtracted that much from the tractors carrying capacity. Also, the counterweighted tractor would be out of balance before its full carrying capacity could be utilized. As pipes to be handled have become larger and heavier they have gone far beyond the ability of the counterbalanced tractor to maintain itself in equilibrium. Another solution has been to use much larger and heavier tractors. These are very expensive and they become considerably more expensive in proportion as their size increases. Today the pipes to be handled have become so heavy that were it not for the present invention, very large specially build mobile lifting devices would have to be designed.

The present invention solves the problem in a manner that may be variously expressed but basically it involves adding no substantial weight to the tractor itself but calls for redistribution of existing Weight in relation to the supporting wheels or tracks. The wheels or tracks are spaced farther apart and the tractor engine and frame are set close to the wheels or tracks on one side and well apart from the wheels or tracks on the other side. Obtaining such a long sought result without adding materially to the tractors weight is a great advantage. It enables utilization of a larger percentage of the carrying capacity of a tractor by redistributing the weight of the tractor and thus providing a tractor that is not easily overbalanced. In this way a considerable increase in effective side-carrying capacity can be achieved at a minimum cost. The structure of the present invention may be incorporated into already-existing tractors or into new tractors as &

they are built. The effective side capacity of any tractor can be increased around 50% or even more, at an "increase of only about 5% or 10% over the original cost of the tractor.

What the present invention does is to provide an asymmetrical tractor. The supporting track or wheel means on the boom side of the tractor is spaced much farther from the tractor body than is the track or wheel means on the other side of the tractor. This moves the center of gravity of the unloaded tractor adjacent to the closer track, instead of halfway between the tracks as on theprior art tractors.

The present invention does not bar use under extreme conditions of the prior art counterweights but it provides a lifting vehicle which will handle without counterweights, loads formerly impossible without them. The tractor of the present invention can carry much heavier loads before it is overbalanced.

Not only does this shift in weight counteract overbal ancing, another advantage is the additional leverage which the tractor can get on the pipe, because the angle between the cable and the boom is greater.

By incorporating this invention into a typical-tractor and shifting the tread on the boom-side out only twentytwo inches the capacity of one tractor was increased from approximately 57,000 pounds to approximately 80,000 pounds. The alteration was made at a cost of $1,500 on $12,000 stock tractor. The installation cost may .be reduced about two-thirds by incorporating the invention into the tractor during manufacture.

Other advantages and objects of the invention will appear from the following description of a preferred form thereof. This detailed description is not intended to narrow the invention beyond the scope of the claims.

in the drawings:

Fig. 1 is a view in elevation looking at the rear of a tractor embodying the principles of the invention. The tractor is shown holding a pipe above a trench where it is to be deposited.

Fig. 2 is atop plan view of the tractor sho Fig. 3 is an enlarged plan view, partly in section along the line 3-3 in Fig. 1, showing in more detail the parts which are extended; to conserve space, the top of the boom has been broken away.

Fig. 4 is a further enlarged plan view of a portion of Fig. 3, showing in more detail the axle that drives the offset track on the boom side of the tractor.

Pig. 5 is a view in side elevation on the scale of Fig. 3, looking at Fig. 3 from the right. The boom has been broken away in order to conserve space while showing the tractor on a relatively large scale.

Fig. 6 is a diagrammatic view showing'how the boom may be hinged to the tractor at a point opposite to what it is in Fig. l.

The tractor 16 shown in the drawings, and now to be described, is substantially a standard track-laying type, with a side boom or crane as improved by incorporating into it the present invention. The invention applies to any tractor and any crane and is not limited to those illustrated here in describing the invention. Since these are both well known devices in this art it will not be necessary to describe in great detail the tractor parts, except as they are directly concerned by or are changed by this invention.

The tractor 10 includes a body member 11 which supports an engine 12, a seat 13 for the operator, and standard controls 14 for operating both the movement of the tractor and the raising and lowering of the crane :boom. The body 11 and all its associated parts are basicaliy the same on most tractors.

On each side of the body 11 are mobile means for advancing the tractor 10 over the ground. In the form here illustrated these mobile means include a pair of wn in Fig. l.

of the tracks. usual location closely adjacent the body.

38 is abroad flaring brace member 40.

, a a endless tracks 22 and 23. Wheels may be used in place The track frame 29 is positioned at the The track frame 21, however, is offset'a substantial distance away from the body 11, and its axle and supporting members are correspondinglyextended. This offset makes the tractor asymmetrical, shifts the balance of thetractor so-that'the center'of gravity is near the closer track frame 2 0, and enables more effective use of the tractors weight;

' 'Another way of expressing this is to say that the track frames and 21 are spaced farther apart than is usual 'and the body'11 is then set closer to the track 22 than to the track 23'. The crane extends out beyond the track While I'have shown the partsarranged so thecrane extends out beyond the track 23, all theparts may be reversed so that the body 11 is set close to the track 23 and the crane is set to extend out beyond the track 22.

This asymmetrical construction may be achieved in many different ways. The drawings show one practical way of doing this. Here the axle, axle housing, brace,

' and steadying members on one side of the tractor it are alllengthened, so that the track 23 is shifted over about two feet further out from the body than the track 22. Otherwise, the track frame 21,. track 23, and all its assembled parts remain unchanged.

A'comparison of the two sides oft-the tractor 10, referreing to Figs. 3 and 4, will illustrate what can be done.

Before rebuilding the'tractor to achieve the present invention, the tractor was symmetrical. In other words, both sides were like the left-hand side of Fig. 3, with both track frames and both tracks positioned close to the body 11.

The drive and connecting links for the track 22 and its frame 20 include a stationary, solid, tapered central supporting-shaft 39. Around'this motionless shaft 36 moves a tapered tubular drive axle 31. At its inner end athe axle 31 receives its drive from the driven gear 32. '-It transmits this drive to the sprocket wheel 33 secured to. its outer end. The sprockets teeth engage openings 34 in the track 22 and propel the track. The axle 31 and its gear 32 are contained in a housing 35, which protects them from dust. Idler wheels 36 and 37 along the frame 20 .help support the track 22. 'At the other end of the frame 20 a brace 38 connects the body 11 to the frame 20. In between the shaft and the brace Its wider end 41 is secured to the frame 20, and its narrow inner end 42 is securedaround the stationaryaxle 39. The inven- 'tion may be practiced on tractors where the tracks are free to oscillate,.as well as where the tracks are fixed in relation to each other.

Figs. 3 and 4 show the changes which may be made in theioifset side of the tractor. What would bethe solid shaft 30 has been lengthened and has the two tapered 7 housing on the other side is split, and a tubular sleeve 601s welded between the inner housing end 61 and the outer housing .end 62.

Idler wheels63 and 64' help support the track 23. An extended front brace 65 may be a new integral member or it 'rnaybe'a member like the brace 38 having an extension piece welded to it similar to that used with the axle 30. Thebrace may also be extended in a similar way or it'may be a new piece of the desired dimensions. The boom (see Figs. 1 and 2) may comprise two armsz71 and. 72 pivoted on brackets 73 and 74 adjacent the offsettrack frame member 21. The arms converge at the upper end 75. To get the benefit of the invention, the boom is located on the offset side. A lifting cable 76 passes over a block 77jwhichis'suspended from the upper endi of the boom 70; It is run around the lower block 78 which supports suitable tackle 79. The

' cable 76 runs .under a pulley 80 and across the frame 11 toa winch 81 on the other side of the tractor.

A second cable 82 may be used to lift and lower the boom 70. The winch 81 has another drum that controls the length of the cable 82 between a block 84 at the top of the boom 7 ti and a block 85 adjacent the winch.

The tractor 10 operates similar to the standard pipelaying tractor, but has greater capacity because it will remain in balance while lifting a heavier load. The winch 81 controls, on separate drums, the length of both cables 76 and 82. In this manner the boom 70 may be raised and lowered and the block 78 may be raised and lowered relatively to the boom 70.

Before pipe is lifted, the center of gravity'of the tractor will be about along the line A-'A in Fig. 1. How much the resultant center of gravity will shift depends, of course, on the weight of the pipe 95. It may shift over into the vicinity of the center line B-B of the tractor body 11. A very heavy load will shift it over into the vicinity of the line CC on the other 'side of the tractor, which is much farther away from the line BB than is the line A A. Only a very heavyload will overbalance the tractor. In the normal, symmetrical tractor, the initial'center of gravity will be closer to the line BB at the start, and under a heavy load will shift over beyond the line C-C and will overbalance the tractor.

Due to the offsetting of 'theboom-side track'23,'the moment of the tractor increases in proportionately great amounts as the weight of thepipe moves the centerof gravity toward the line C.C. The effective counterbalance of the tractor is increased because the moment is a product of weight and its distance from thecenter of gravity. Stability will be maintained so long as the centerof gravity is between the tracks, because no weight centered in between the tracks can tip over the tractor. Thus, the increasing moment and the' spread of the tracks both act to increase stability. The present invention specifies a particular type of asymmetry, Withthe boom-side track being the one that is offset.

-In the tractor shown in the drawings, one track 22 is closely adjacent the body 11; however, the invention includes an arrangement where there is' more.

space between the body and the track so long'as the track nearest the working end of the boom is spaced sub:

' stantially further from the body than'the other track The diagrammatic sketch in Fig. 6 shows that it is not essential to the present invention 'for'the boom to be pivoted adjacent, the track farthest removed from the body member 11. InFig. 6 the boom is pivoted on the opposite side in relation to' what it' is in Fig.1. It is obvious that it may be pivoted at. any convenient place on the tractor so long as the working end of the boom projects out over the track which is offset farthest from the body member 11.. V

Summarized, what this invention includes (see ,Figs.

1 and 3) is a mobile self-propelled vehicle 10, having mobile support means 22 and 23 on each side; a body portion 11 containing the power plant between the mobile support means 22 and 23; a frame means 35, 38 connecting one mobile support means 22 to the body portion 11 and another frame means6tl, 65' connecting the other mobile support means 23 adjacent the other side of the body portion 11; the frame means 60, 65 being wider than the other frame means 35, 38 so i that the body portion 11 is supported closer to the mobile means 22 than to the mobile means 23; and with a boom 70 having its base operatively secured to thevehicle 10 adjacent the mobile support means 23 spaced farthest from the body 11; and having rigging 76, 82 mounted on the vehicle 10 and arranged to support the end of the boom 70 in operative position outboard in relation to the mobile support means 23.

I claim:

1. A tractor adapted to raise, carry, and lower heavy objects beyond one edge thereof, comprising a body member including a source of motive power and controls therefor; mobile means extending fore and aft on each side of said body member giving four point support to said body member and on which it is able to be moved over the ground, the fore and aft extending mobile means on one side thereof being spaced close to said body member and the other of said fore and aft extending mobile means being spaced outwardly a substantial distance away from said body member; a boom pivoted to said tractor on said outwardly spaced fore and aft extending mobile means and extending outwardly sidewise beyond the edge of said tractor and said outwardly spaced mobile means; a winch mounted on said tractor and extensible lifting means connecting said boom to said winch.

2. A tractor adapted to raise, lower, and carry heavy objects of? one side thereof, comprising a body member including a source of motive power and controls therefor; track-supporting means on each side of said body member, one of said track-supporting means being spaced farther from the fore and aft center line of said body than the other track-supporting means; endless tracks on said tracksupporting means, adapted to move around a closed path and thereby advance said tractor; a boom operatively pivcted to said farther-spaced track-supporting means; a winch mounted on the opposite side of said tractor; and extensible lifting means connecting said boom to said winch; the center of gravity of the entire tractor being in close proximity to the closer track so that loads large in proportion to the weight of the tractor can be lifted and carried by the boom when swung outside the farther track.

3. A tractor adapted to raise, lower, and carry heavy objects at one side thereof, comprising a body including a source of motive power and controls therefor; tracksupporting means located on each side of said body, one of said track supporting means being spaced farther from the fore and aft center line of said body than the other; an endless track on each said track-supporting means; means to propel said tracks; a boom pivoted to the outside edge of said farther-spaced track-supporting means; a winch mounted on said tractor; and an extensible lifting means connecting said boom to said winch.

References Cited in the file of this patent UNITED STATES PATENTS 337,462 Valentine Mar. 9, 1886 $08,155 White Nov. 7, 1893 849,106 Castagnos Apr. 2, 1907 984,155 Preston Feb. 14, 1911 1,353,841 Neighbour Sept. 28, 1920 1,520,397 Best Dec. 23, 1924 1,606,628 Gros Nov. 9, 1926 1,676,645 Funk July 10, 1928 1,851,346 Brown Mar. 29, 1932 1,877,556 Clark et a1 Sept. 13, 1932 1,925,169 Berg Sept. 5, 1933 2,261,870 Cardwell Nov. 4, 1941 2,425,663 Wooldridge Aug. 12, 1947 2,513,942 Johnson et a1. July 4, 1950 

